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J Piironen

Publications and source records attributed to J Piironen.

14 recordsLinked to original sources
PubMed2003

Phenotypic variation in growth trajectories in the Arctic charr Salvelinus alpinus.

Animals with determinate growth have shown little variation in individual growth patterns, but similar analyses for animals with indeterminate growth have been lacking. We analysed the amount of phenotypic variation in growth patterns across ages among individuals of a hatchery-based population of Arctic charr, Salvelinus alpinus, Salmonidae, using the infinite-dimensional model and including the effects of group size structure. There was little phenotypic variation in growth trajectories: individuals that were small (in relation to the mean) early in life were among the smallest 2.5 years later. If the genetic variation reflects phenotypic variation, not much evolutionary change can be expected. Our results show that there are ecological conditions that determine the strong covariation of size across ages, most likely size-related dominance behaviour, which can mask the true variation of growth patterns. Thus, social interactions can have strong evolutionary effects on traits not directly involved in the behavioural interactions.

Adaptation, Physiological↗
PubMed2000

The one that did not get away: individual assignment using microsatellite data detects a case of fishing competition fraud.

Assignment of an individual to the population from which it most probably originated based on its multilocus genotype has been widely applied in recent years. In this study, individual assignment based on microsatellite data was used to identify a case of fishing competition fraud. Despite the fact that the true population of origin was most probably not among the reference populations, recent modifications of the assignment tests were used in confidently excluding (p < 0.0001) the possibility of a 5.5 kg salmon (Salmo salar) originating from the fishing competition location, Lake Saimaa (south-east Finland). In fact, the probability of the suspect salmon originating from one of the regions that supply most of Finland's fish markets was found to be over 600 times higher than it originating from Lake Saimaa. When presented with this evidence, the offender confessed to purchasing the salmon at a local fish shop and criminal charges were laid. This study emphasizes the potential practical application of the individual assignment procedure, in particular the usefulness of confidently excluding populations as the origin of an individual. A similar strategy could be also used, for example in suspected cases of illegal poaching, in order to assign or exclude individuals from originating from a claimed population.

Alleles↗
PubMed2000

Genetic lineages and postglacial colonization of grayling (Thymallus thymallus, Salmonidae) in Europe, as revealed by mitochondrial DNA analyses.

In stark contrast to other species within the Salmonidae family, phylogeographic information on European grayling, Thymallus thymallus, is virtually nonexistent. In this paper, we utilized mitochondrial DNA polymerase chain reaction-restriction fragment length polymorphism (mtDNA PCR-RFLP) and sequence variation to infer the postglacial dispersal routes of T. thymallus into and within northern Europe, and to locate geographically, potential evolutionarily distinct populations. Mitochondrial analyses revealed a total of 27 T. thymallus haplotypes which clustered into three distinct lineages. Average pairwise interlineage divergence was four and nine times higher than average intralineage divergence for RFLP and sequence data, respectively. Two European grayling individuals from the easternmost sample in Russia exhibited haplotypes more genetically diverged from any T. thymallus haplotype than T. arcticus haplotype, and suggested that hybridization/introgression zone of these two sister species may extend much further west than previously thought. Geographic division of the lineages was generally very clear with northern Europe comprising of two genetically differentiated areas: (i) Finland, Estonia and north-western Russia; and (ii) central Germany, Poland and western Fennoscandia. Average interpopulation divergence in North European T. thymallus was 10 times higher than that observed in a recent mtDNA study of North American T. arcticus. We conclude that (i) North European T. thymallus populations have survived dramatic Pleistocene temperature oscillations and originate from ancient eastern and central European refugia; (ii) genetic divergence of population groups within northern Europe is substantial and geographically distinct; and (iii) the remainder of Europe harbours additional differentiated assemblages that likely descend from a Danubian refugium. These findings should provide useful information for developing appropriate conservation strategies for European grayling and exemplify a case with a clear need for multinational co-operation for managing and conserving biodiversity.

Animals↗
PubMed2000

Effects of phosphorolytic and cell wall-degrading enzymes on the performance of growing broilers fed wheat-based diets containing different calcium levels.

A study was conducted to determine the cumulative effects of phosphorolytic enzymes, cell wall-degrading enzymes, and citric acid and Ca levels on feed intake, BW gain (BWG), feed conversion, intestinal viscosity, and toe ash of broilers (d 1 to 21) fed wheat-based diets. Broilers were fed the following six diets at either 0.59, 0.69, or 0.79% Ca: 1) a negative control (NC) diet, 0.17% available P; 2) NC + 750 phytase units/kg diet; (3) phytase + 3,156 units of acid phosphatase/kg diet; 4) phytase + acid phosphatase + 1,900 units of pectinase/g diet; 5) phytase + acid phosphatase + pectinase + 3% citric acid; and (6) NC plus 0.24% available P. The 18 dietary treatments were fed to four pen replicates of eight birds each. Phytase addition at the low Ca level increased BWG, improved feed intake and conversion and toe ash, and reduced intestinal viscosity and ileal length. Subsequent addition of acid phosphatase, at 0.69% Ca, resulted in increases in BWG, 42%; feed intake 32%; feed conversion 7.5%; and toe ash, 63% over the NC diet. Pectinase addition produced further improvements in 21-d BWG and feed intake at 0.59 and 0.79% Ca, increased toe ash in chicks fed 0.79% Ca, and reduced intestinal viscosity. Supplementation of wheat-based 0.17% available P diets with phytase and acid phosphatase and with appropriate concentrations of pectinase, citric acid, and Ca significantly improved BWG, feed intake and conversion and intestinal viscosity over the 0.41% available P diets. Bone mineralization of chicks fed phytase + acid phosphatase and 0.69% Ca and those fed phytase + acid phosphatase + pectinase + citric acid and 0.59% Ca was similar to that of chicks fed the 0.41% available P diets.

6-Phytase↗
PubMed2000

Comparison of the efficacies of a novel aspergillus niger mycelium with separate and combined effectiveness of phytase, acid phosphatase, and pectinase in dephosphorylation of wheat-based feeds fed to growing broilers.

Efficacies of phytase, phosphorolytic enzymes (phytase + acid phosphatase), an enzymic "cocktail" (phytase + acid phosphatase + pectinase + citric acid), a novel Aspergillus niger (fungal) mycelium (FM), and FM enriched in phytase and antioxidants were investigated in growing broilers (Days 1 to 21) fed wheat-based diets. Broilers were fed the following seven diets at 0.69% Ca: 1) a negative control diet, 0.17% nonphytate P (NPP); 2) Diet 1 + 750 phytase units/kg diet; 3) Diet 1 + 750 phytase units + 3,156 units acid phosphatase/kg diet; 4) Diet 1 + 750 phytase units + 3,156 acid phosphatase units + 1,900 units of pectinase/g diet + 3% citric acid; 5) Diet 1 + 4% FM; 6) Diet 1 + 4% FM + 1,300 phytase units + 2% ascorbic acid and 1% of glucose oxidase; and 7) a positive control diet (Diet 1 + 0.24% NPP from dicalcium phosphate). The dietary treatments were fed to four pen replicates of eight birds each. Prior to feed formulation, mycelium and antioxidants dosages were optimized on Diet 1 by an in vitro technique and an experimental design module of a statistical software package. Phytase addition increased BW gain (BWG), feed intake, and P retention. Subsequent addition of acid phosphatase resulted in further increases in BWG, feed intake, and toe ash and reduced digesta viscosity; however, neither P nor Ca retention were improved. Body weight gain and feed intakes superior to those found in chicks fed Diet 7 were observed in birds receiving the cocktail of enzymes (Diet 4) or FM. Chicken fed Diet 6 had the highest percentage of toe ash and retained 76 and 51% of P and Ca, respectively. Supplementation of wheat-based 0.17% NPP diets with FM increased bursa of Fabricius weights and reduced the intestinal surface covered by Peyer's patches.

6-Phytase↗
PubMed1999

Comparison of Aspergillus niger phytase and Trichoderma reesei phytase and acid phosphatase on phytate phosphorus availability in pigs fed on maize-soybean meal or barley-soybean meal diets.

The efficacy of Aspergillus niger (APhy) phytase, Trichoderma reesei (TPhy) phytase and acid phosphatase (TAcPh) preparations in improving the utilization of phytin-phosphorus in the maize-soybean meal (SBM) or barley-SBM (800:200 g kg-1) diets was studied in two separate digestibility and balance trials with ten growing pigs using 5 x 5 Latin square designs. The positive control diet contained a total phosphorus (P) of 6.5 g kg-1, while the negative control as well as the APhy, TPhy and TAcPh supplemented diets which did not contain additional inorganic-P, had a total P of 4.1 g kg-1. The APhy and TPhy supplements provided phytase activity of 1000 PU g-1 together with AcPh of 8000 HFU g-1. TAcPh at a level of 8000 HFU g-1 was the only addition to one diet. The intrinsic phytase activity of barley was 355 PU g-1 while maize and soybean meal showed no phytase activity. Phytase supplements of the APhy and TPhy sources increased ash digestibility in both diets but had only a minor effect on nitrogen utilization. The addition of phytase improved absorption of P by 21%-units in barley-SBM diet and 29%-units in maize-SBM diet, without any difference between the two phytase sources. The retained P in diets with phytase was higher than in diets without phytase, 4.4 (APhy), 4.5 (TPhy) vs. 2.9 g d-1 in barley-SBM-diets and 3.7 (APhy), 4.0 (TPhy) vs. 1.8 g d-1 in maize-SBM-diets. No difference was found between the two sources of phytase. TAcPh without additional phytase did not show any effect on P absorption or retention. Ca absorption and retention were improved due to the phytase treatments. Supplementing pig diets with either APhy or TPhy sources seems to be equally effective in enhancing the availability of phytate-P. Consequently, these supplements can reduce the P-excretion of pigs by 32-40% as compared with the diet supplemented with inorganic-P.

6-Phytase↗
PubMed1990

Helium-neon laser therapy in the prevention of postoperative swelling and pain after wisdom tooth extraction.

Seventeen patients with symmetrically embedded lower wisdom teeth were selected for this study, intended to evaluate the local effect of soft laser therapy on postoperative pain. Both lower third molars were removed in the same operation. The test side, chosen by lot, was treated using a helium-neon laser (632,8 nm, 8 mW, 50 Hz) for 2 minutes. The other side served as the untreated control side. Facial swelling was measured using a modification of the face-bow technique. Postoperative pain was estimated using a visual analogue scale (VAS). When it became apparent that conventional statistical analysis was revealing no difference in postoperative swelling and pain between the test and the control groups, the study was discontinued for ethical reasons.

Adult↗
PubMed1989

Regeneration of cold, warmth and heat-pain sensibility in human skin grafts.

Recovery of cold, warmth and heat-pain sensations in skin grafts was studied psychophysically in 22 patients who had had split skin grafts transplanted over muscle fascia 1 to 4 years earlier. A thermal stimulator based on the Peltier principle and controlled by a microprocessor was used to measure the thermal sensitivity of the grafts. Control measurements were obtained from the corresponding opposite side of the body. Cold sensitivity was present in 14 grafts (from 1-4 years old). However, with one exception, the threshold for cold sensation remained higher than normal in all patients. Warmth sensitivity was present in 6 grafts (from 1-4 years) which were all also sensitive to cold. Heat-pain sensitivity was present in 8 grafts. If the warmth and heat-pain sensibility had recovered, the sensation threshold was closer to the normal value than that for cold. In 7 grafts (from 1-3 years) no recovery was obtained.

Adult↗
PubMed1986

Anaerobic wintering of crucian carp (Carassius carassius L.)--II. Metabolic products.

In long-term experimental anoxia (up to 140 days) crucian carp excreted ethanol and acetic acid. The maximum concentration of ethanol found in fish blood was ca 0.1%. The excretion rate of ethanol at temperatures from -0.5 to +5 degrees C was ca 25 micrograms/g fish wet wt/hr, but increased rapidly with increasing temperature. At 2 and 5 degrees C the ethanol excretion rate was independent of fish size, but at 12 and 18 degrees C a higher rate was observed in smaller fish. The decrease of water pH below 5 in the experimental vial during long anoxia was assumed to be due to excretion of acid compounds by the fish.

Acclimatization↗
PubMed1980

Secondary reconstructive surgery in burns.

The material presented consist of 143 late sequelae of thermal burns. The majority of the patients were children, and the upper extremities or the face were most frequently involved. As only 41% of the burns had been primarily grafted, scar contracture was the main indication for secondary surgery in 83% of the patients. The importance of early correct evaluation of the burn and active primary treatment is stressed, especially in deep dermal burns (II degree). Release by complete excision or incision with skin grafting was the most frequent method of reconstruction. The treatment of contractures, hypertrophic scars and keloids, as well as various factors influencing the selection of the reconstructive method and time are discussed.

Adolescent↗